1. Field of the Invention
This invention relates to a decontamination system for removal of hazardous substances such as asbestos, lead, and toxic chemicals. Moreover the system particularly relates to a decontamination unit with diffused airflow in the entry chambers formed thereby and circulating through the containment area. The system has high versatility and is applicable to almost any environment or architecture, including occupied buildings, densely populated areas, and worksites in crawl spaces and small passageways.
2. Information Disclosure Statement
Several patents descriptive of decontamination systems are known to the inventor hereof. The patents are as follows:
______________________________________ Patent Inventor Issue Date ______________________________________ 4,604,111 Natale 8/1986 4,801,312 Mateson 1/1989 4,905,578 Curtis et al. 3/1990 4,922,806 Newman et al. 5/1990 4,963,170 Weber et al. 10/1990 4,993,313 Newman et al. 2/1991 5,009,685 Wilson et al. 4/1991 ______________________________________
The U.S. Pat. No. 4,604,111 to Natale shows a system and a method of use thereof for enclosing a source of hazardous particulate matter along with a decontamination chamber space. Air flow is provided through the enclosure and through the decontamination chamber. This air is then filtered and exhausted. However, the air inlet and outlet of the decontamination chamber are positioned such that an uneven or non-uniform pattern of air flow through the decontamination chamber and through the decontaminated areas may result before the air is exhausted.
The U.S. Pat. No. 4,801,312 to Mateson teaches a decontamination space having a plurality of rooms and air locks between the rooms and a work space wall with laminar air flow at the wall.
The U.S. Pat. No. 4,905,578 to Curtis et al. teaches an air handling device for contaminated areas in which air is removed therefrom and returned with make-up air after filtration.
The U.S. Pat. No. 4,922,806 to Newman and Natale teaches a construct using the structure similar to patent of Natale '111, but having a flap for sealing upon loss of negative air pressure in the work area.
The U.S. Pat. No. 4,963,170 to Weber et al. teaches the using of HEPA filters to purify inflowing and outflowing air from the work area.
The U.S. Pat. No. 4,993,313 to Newman and Natale teaches, upon power failure, the maintenance of negative pressure within an enclosed area and facilitates the quick exit of workmen therefrom.
The U.S. Pat. No. 5,009,685 to Wilson et al. teaches the use of a decontamination unit mounted between a work area and a dressing room with negative air pressure in the work area and positive air pressure in the decontamination unit both maintained by filtered air pumps.
With all the prior advances in the art several technological problems remain. Typical thereof is that of the even diffusion of air throughout all parts of the containment area. Several of the above-cited systems, including the system of Natale, permit particulate-laden air to accumulate in the corners and to form a health hazard. Other system defects include the lack of control of the volume of makeup air and accuracy in maintaining the differential pressure between the negative pressure of the containment area and the external ambient pressure.
Of special note is the emergency mode of operations. Here the technological problems that arise during power failure and upon the occurrence of a fire are addressed. Workmen in the containment area need safe haven, and the public needs protection from the contaminated air in the containment area. These are the technological shortfalls of the above systems and are addressed hereinbelow.
In addition to the above background certain aspects of hazardous substance removal are highly regulated by both Federal and State agencies, notably the Environmental Protection Agency, the Occupational Safety and Health Administration, and various State Departments of Environmental Protection. All equipment described herein meets or exceeds the guidelines of the various agencies.